A catheter assembly is used at the time of performing infusion to a patient or the like. This kind of catheter assembly includes a hollow outer needle (catheter), an outer needle hub (catheter hub) fixed to a proximal end of the outer needle, an inner needle inserted into the outer needle and having a sharp needlepoint at a distal end, and an inner needle hub fixed to a proximal end of the inner needle. In the case of performing infusion to the patient by using the catheter assembly, a blood vessel of the patient is punctured with the outer needle together with the inner needle. After puncturing, the inner needle is pulled out from the outer needle while keeping the patient punctured with the outer needle. Next, a connector provided at an end portion of an infusion tube is connected to a proximal end of the outer needle hub, and infusion material is supplied into the blood vessel of the patient via the infusion tube, outer needle hub, and outer needle. An example of such a catheter assembly used as a peripheral intravenous catheter is disclosed in Japanese Patent No. 5108882.
A central intravenous catheter, a peripherally inserted central catheter (PICC), a midline catheter, etc. are known as catheters having a length longer than the peripheral intravenous catheter, indwelled inside a blood vessel of a patient, and used to administer infusion solution. Therefore, when respective lengths of the inner needle and the catheter of the catheter assembly are long, it is possible to use as the central intravenous catheter, PICC, midline catheter, etc.